EP3556304B1

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Publication number: EP3556304B1
Application number: EP19165622.2A
Authority: EP
Inventors: Joseph GUERRERA
Original assignee: Covidien LP
Current assignee: Covidien LP
Priority date: 2018-03-28
Filing date: 2019-03-27
Publication date: 2024-02-28
Anticipated expiration: 2039-03-27
Also published as: US12023033B2; US20190298370A1; JP7245085B2; EP3545874A1; EP3549535B1; EP3545871A1; US20190298368A1; CN110313954A; JP2019171043A; CN110313960B; US11051820B2; CN110313958B; EP3549535A1; CN110313960A; US20210106334A1; JP7468994B2; CN110313961A; JP2019171044A; US11033273B2; EP3545871B1

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of, and priority to,U.S. Provisional Patent Application Nos.: 62/649,341;62/649,176;62/649,325;62/649,304;62/649,278;62/649,267;62/649,241;62/649,227;62/649,217; and62/649,200, each of which were filed on March 28, 2018.

BACKGROUND

1.Technical Description

The present disclosure generally relates to a surgical stapling instrument and, more particularly, to a surgical anvil assembly for use with a circular stapling instrument and having an anvil head capable of pivoting or tilting to facilitate insertion and/or withdrawal of the anvil assembly relative to the operative site.

2.Background of Related Art

Circular stapling instruments for performing surgical procedures such as anastomoses, hemorrhoidectomies, and mucosectomies are well known. These devices include an anvil assembly having a center rod and an anvil head supported on the center rod. Typically, during a surgical procedure, the tool assembly of the circular stapling instrument is inserted into a tubular section or sections of tissue to join the tissue sections or remove diseased or damaged tissue from within the tissue section. In order to minimize trauma to the tissue section, the anvil head may be pivotally supported on the center rod to reduce the profile of the anvil assembly during insertion and/or removal of the tool assembly from the tissue section. In some circular stapling instruments, a component is fractured during firing to permit tilting of the anvil head relative to the center rod. DocumentWO 2017/096502 A1 discloses a surgical stapling instrument including an anvil assembly. The anvil assembly includes a head assembly pivotally secured to the center rod assembly and movable between a tilted position and an operative position. A coil spring is received about a plunger member for biasing it in a proximal direction. The plunger member comprises a radial extension connected to a drive link which connects it to to the head assembly. DocumentWO 03/030745 A1 discloses an anvil assembly with a biasing member urging it to a tilted position. A drive link and a return link are connected to an anvil post of the anvil assembly.

SUMMARY

The invention is defined in appended claim 1. Specific embodiments are set forth in the dependent claims.
Other features of the present disclosure will be appreciated from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently disclosed surgical anvil assemblies for incorporation into surgical circular stapling instruments are described herein below with reference to the drawings, wherein:

FIG. 1 is a perspective view of an exemplary embodiment of a surgical circular stapling instrument including an embodiment of a surgical anvil assembly of the present disclosure;
FIG. 2 is a perspective view of the circular stapling instrument illustrating a tool assembly including the anvil assembly separated from an elongate body of the circular stapling instrument;
FIG. 3 is a side cross-sectional view of the tool assembly illustrating the anvil assembly mounted to the staple cartridge of a shell of the tool assembly;
FIG. 4 is a perspective view of the anvil assembly;
FIG. 5 is an exploded, perspective view of the anvil assembly;
FIG. 6 is a side cross-sectional view of the tool assembly illustrating the anvil assembly mounted to the staple cartridge with an annular knife in an advanced position;
FIG. 7 is side cross-sectional view of the anvil assembly illustrating the anvil head in a pivoted or tilted condition;
FIG. 8 is a side cross-sectional view of an embodiment of a surgical anvil assembly for incorporation into the circular stapling instrument ofFIG. 1;
FIG. 9A is a first perspective view of an inner member of a locking assembly of the anvil assembly ofFIG. 8;
FIG. 9B is a second perspective view of the inner member of the locking assembly;
FIG. 10 is a perspective view of an outer member of the locking assembly ofFIG. 8;
FIG. 11 is a side cross-sectional view of the anvil assembly ofFIG. 8 illustrating the locking assembly in a distal position;
FIG. 12 is a side cross-sectional view of the anvil assembly ofFIG. 8 illustrating the locking assembly in a proximal position;
FIG. 13 is a perspective view of another embodiment of a surgical anvil assembly for incorporation into the circular stapling instrument ofFIG. 1;
FIG. 14 is a side, perspective view of an anvil center rod of the anvil assembly ofFIG. 13;
FIG. 15 is a perspective view of a resilient leg of the anvil assembly ofFIG. 13;
FIG. 16 is a side view of the resilient leg ofFIG. 15;
FIG. 17 is a side view, with parts shown in phantom, of a trocar being inserted into the anvil center rod ofFIG. 14;
FIG. 18 is a perspective view, with parts shown in phantom, of the trocar being inserted into the anvil center rod ofFIG. 14;
FIG. 19 is a perspective view, with parts shown in phantom, of the trocar fully inserted into the anvil center rod ofFIG. 14;
FIG. 20 is a side cross-sectional view of another embodiment of a surgical anvil assembly for incorporation into the circular stapling instrument ofFIG. 1;
FIG. 21 is a perspective view of a proximal side of a ring assembly of the anvil assembly ofFIG. 20;
FIG. 22 is a perspective view of a distal side of the ring assembly ofFIG. 21;
FIG. 23 is a side cross-sectional view of the anvil assembly ofFIG. 20 illustrating the ring assembly in a distal position;
FIG. 24 is a perspective view of components of another embodiment of a surgical anvil assembly for incorporation into the circular stapling instrument ofFIG. 1;
FIG. 25 is a perspective view of a proximal side of a ring assembly of the anvil assembly ofFIG. 24;
FIG. 26 is a perspective view of a distal side of the ring assembly ofFIG. 25;
FIG. 27 is a partial, side cross-sectional view of the ring assembly ofFIG. 25;
FIG. 28 is a side cross-sectional view of the anvil assembly ofFIG. 24 illustrating the ring assembly in a proximal position;
FIG. 29 is a side cross-sectional view of the anvil assembly ofFIG. 24 illustrating the ring assembly in a distal position;
FIG. 30 is a side cross-sectional view of another embodiment of a surgical anvil assembly for incorporation into the circular stapling instrument ofFIG. 1;
FIG. 31 is a perspective view of a ring assembly of the anvil assembly ofFIG. 30;
FIG. 32 is a perspective, cross-sectional view of the ring assembly ofFIG. 31;
FIG. 33 is a perspective view of components of another embodiment of a surgical anvil assembly for incorporation into the circular stapling instrument ofFIG. 1;
FIG. 34 is a perspective view of an anvil head of the anvil assembly ofFIG. 33;
FIG. 35 is a perspective view of a ring assembly of the anvil assembly ofFIG. 33;
FIG. 36 is a side cross-sectional view of the ring assembly ofFIG. 35;
FIG. 37 is a perspective view of a snap collar of the ring assembly ofFIG. 35;
FIG. 38A is perspective view of a proximal side of a backup member of the ring assembly ofFIG. 35;
FIG. 38B is a perspective view of a distal side of the backup member ofFIG. 38A;
FIG. 39 is a side cross-sectional view of the anvil assembly ofFIG. 33 illustrating the ring assembly in a proximal position;
FIG. 40 is a side cross-sectional view of the anvil assembly ofFIG. 33 illustrating the ring assembly in a distal position;
FIG. 41 is a side cross-sectional view of an embodiment of a surgical anvil assembly according to the present invention for incorporation into the circular stapling instrument ofFIG. 1;
FIG. 42 is a perspective view of a distal portion of an anvil center rod of the anvil assembly ofFIG. 41;
FIG. 43 is a side view of a linkage arm of a pivoting assembly of the anvil assembly ofFIG. 41;
FIG. 44 a side cross-sectional view of the anvil assembly ofFIG. 41 illustrating the anvil assembly in a tilted condition;
FIG. 45 is a side cross-sectional view of another embodiment of a surgical anvil assembly for incorporation into the circular stapling instrument ofFIG. 1;
FIG. 46 is an enlarged view of a pivot member of the anvil assembly ofFIG. 45;
FIG. 47 is another side cross-sectional view of the anvil assembly ofFIG. 45;
FIG. 48 is an enlarged view of a cam latch of the anvil assembly ofFIG. 47;
FIG. 49 is a perspective view of another embodiment of a surgical anvil assembly for incorporation into the circular stapling instrument ofFIG. 1;
FIG. 50 is a perspective view of a proximal side of an anvil head of the anvil assembly ofFIG. 49;
FIG. 51 is a side view of a cam latch of the anvil assembly ofFIG. 49;
FIG. 52 is a side cross-sectional view of the anvil assembly ofFIG. 49 illustrating the anvil head in a tilted condition;
FIG. 53 is a side cross-sectional view of another embodiment of a surgical anvil assembly for incorporation into the circular stapling instrument ofFIG. 1 illustrating a ring assembly thereof in a proximal position;
FIG. 54 is a side cross-sectional view of the surgical anvil assembly ofFIG. 53 illustrating the ring assembly thereof in a distal position; and
FIG. 55 is a side cross-sectional view of the surgical anvil assembly ofFIG. 53 illustrating the ring assembly after a retraction of an annular knife.

DETAILED DESCRIPTION

The presently disclosed anvil assemblies for use with various circular stapling instruments will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. In this description, the term "proximal" is used generally to refer to that portion of the instrument or surgical anvil assembly thereof that is closer to a clinician, while the term "distal" is used generally to refer to that portion of the instrument or surgical anvil assembly thereof that is farther from the clinician. In addition, the term clinician is used generally to refer to medical personnel including doctors, nurses, and support personnel.
The exemplary surgical stapling instrument includes a handle assembly, an elongate body or adapter, and a tool assembly coupled to the adapter. The tool assembly includes a shell assembly and an anvil assembly mounted with respect to the shell assembly. The anvil assembly includes a center rod releasably couplable to the elongate body and an anvil head which is pivotally coupled to the center rod. The anvil head is movable between a pre-fired, untilted or operative condition and a post-fired, tilted or pivoted condition. The anvil head is locked in the pre-fired position until an annular knife of the tool assembly is advanced, which frees the anvil head to pivot or rotate relative to the center rod towards the pivoted condition. The present disclosure provides,inter alia, various embodiments of mechanisms for unlocking the anvil head from the anvil center rod, and various embodiments of mechanisms that drive the rotation of the anvil head upon being unlocked from the center rod.
Referring initially toFIGS. 1-2, an exemplary embodiment of a circular stapling instrument for incorporating the surgical anvil assemblies of the present disclosure is illustrated and shown generally ascircular stapling instrument 10. Thecircular stapling instrument 10 includes ahandle 12, an elongate body oradapter 14 extending from thehandle 12, and atool assembly 16 coupled to theadapter 14. Thehandle 12 may be electrically powered including a motor and associated gears and linkages to control operation of the staplinginstrument 10. Thehandle 12 incorporates agrip 18 and a plurality ofactuation buttons 20 which may be activated to control various functions of the staplinginstrument 10 including, e.g., approximation of thetool assembly 16 and firing of staples. Thegrip 18 may support a battery pack (not shown) which powers thehandle 12. In embodiments, thecircular stapling instrument 10 may be powered via an external power source.
In embodiments, theadapter 14 is releasably coupled to thehandle 12 and includes a plurality of drive mechanisms (not shown) that translate power from thehandle 12 to thetool assembly 16 in response to actuation of theactuation buttons 20 to effect operation, e.g., approximation and firing, of thetool assembly 16. Theadapter 14 also includes ananvil retainer 22 or trocar that extends from a distal portion of theadapter 14 and is movable between retracted and advanced positions. Theanvil retainer 22 is couplable to thetool assembly 16. Commonly assignedU.S. Patent Nos. 9,247,940;9,055,943; and8,806,973, andU.S. Publication No. 2015/0014392 disclose exemplary embodiments of powered handles and adapters suitable for use with the staplinginstrument 10. Alternately, the elongate body oradapter 14 may be non-removably secured to thehandle 12.
It is also envisioned that thehandle 12 may be manually powered. Examples of manually powered handle assemblies are described in commonly assignedU.S. Patent Nos. 8,789,737;8,424,535; and8,360,295.
Referring toFIGS. 3-5, in conjunction withFIG. 2, thetool assembly 16 includes ashell 24 and asurgical anvil assembly 26 releasably mounted to theshell 24. Theshell 24 supports anannular staple cartridge 28 and anannular knife 30 internal of thestaple cartridge 28. Thestaple cartridge 28 includes a plurality ofstaple receptacles 32 each accommodating anindividual staple 34 and astaple pusher 36 for ejecting thestaples 34 from thestaple cartridge 28 upon firing of theinstrument 10.
Theanvil assembly 26 shares common features with the anvil assembly disclosed in commonly assignedU.S. Patent No. 8,540,132. As best depicted inFIGS. 3-5, theanvil assembly 26 includes ananvil center rod 38 and ananvil head 40 pivotally mounted to theanvil center rod 38. Theanvil head 40 is adapted to pivot between a first operative condition as depicted inFIGS. 4 and6, and a second pivoted or tilted condition as depicted inFIG. 7. Theanvil center rod 38 includes a pair of distal spacedarms 42 having transverse bores 44 that receive a pivot member, such as, for example, apivot pin 66, therethrough. Theanvil head 40 is pivotably coupled to the distal spacedarms 42 via thepivot pin 66.
Theanvil assembly 26 further includes aplunger 46, aplunger spring 48, and a cam latch orcam plate 50. Theplunger 46 is at least partially received within theanvil center rod 38, e.g., between the spacedarms 42, and is spring biased in a distal direction by theplunger spring 48. Theplunger 46 includes aplunger finger 52, which engages thecam latch 50 to provide a distally-oriented force on thecam latch 50.
Theanvil head 40 includes ahousing 54 defining arecess 70 therein, and apost 56 extending proximally from a center of thehousing 54. Thehousing 54 has an anviltissue contact surface 58 defining a plurality of staple deforming pockets 72. Thepost 56 of theanvil head 40 includes a pair of spacedpost arms 60 defining aslot 62 and transverse bores 64 extending through the spaced postarms 60. As briefly mentioned above, theanvil center rod 38 is at least partially positioned about thepost 56 and coupled to theanvil head 40 through thepivot member 66 which extends through respective transverse bores 44, 64 of the distal spacedarms 42 of theanvil center rod 38 and thepost 56 to pivotally couple theanvil head 40 to theanvil center rod 38. In addition, thecam latch 50 is received within theslot 62 of thepost 56 and coupled to theanvil center rod 38 and thepost 56 via thepivot member 66 which extends through apin opening 68 of thecam latch 50.
Referring now toFIGS. 4-6, theanvil assembly 26 further includes abackup member 76 and acut ring 78 attached thereto. Thebackup member 76 and thecut ring 78 are moved together within therecess 70 of theanvil head 40 upon application of a force thereto, e.g., during advancement of theannular knife 30 of thetool assembly 16 during firing of theinstrument 10. Thebackup member 76 includes anannular body 79 and a pair of diametricallyopposed fingers 98 extending radially inward from theannular body 79. Theannular body 79 of thebackup member 76 is axially movable, but pivotally fixed within therecess 70 of theanvil head 40.
Thefingers 98 are engaged by the spacedarms 42 of theanvil center rod 38 to prevent thebackup member 76 from moving in a proximal direction and to maintain theanvil head 40 in the operative condition (e.g., untilted) until theannular knife 30 is actuated. More specifically, when thebackup member 76 is in the proximal position, as shown inFIG. 3, thefingers 98 of thebackup member 76 sit on or abut a distal surface of the spacedarms 42 of theanvil center rod 38, whereby rocking or pivotal movement of theanvil head 40 relative to theanvil assembly 26 is prevented. Pivotal movement of theanvil head 40 relative to theanvil center rod 38 is permitted only after thefingers 98 are distally spaced from thearms 42 of theanvil center rod 38.
Thebackup member 76 further includes a pair of diametricallyopposed cam shelves 99 extending radially inward from theannular body 79. Thecam shelves 99 capture thecam latch 50 therebetween to rotationally fix thecam latch 50 to thebackup member 76. In this way, as thecam latch 50 rotates or pivots, so does thebackup member 76 and theanvil head 40 as a whole. Thebackup member 76 may be formed from a hard material such as metal, although other materials of construction are envisioned.
Thecut ring 78 of theanvil assembly 26 includes a disc-shapedannular body 104 defining acentral aperture 106 for reception of thebackup member 76. Thus, movement of thebackup member 76 between the untilted and tilted conditions causes corresponding movement of thecut ring 78. In embodiments, thecut ring 78 may be formed through a molding process, e.g., an injection molding process, and may be fabricated from a material having a durometer which permits theannular knife 30 to pierce through theannular body 104 and bottom out against thebackup member 76. Suitable materials of thecut ring 78 include polypropylene or polyester. Other materials are contemplated.
Prior to firing of the staplinginstrument 10, thebackup member 76 is in its retracted or proximal position with thecut ring 78 secured to thebackup member 76 in the aforedescribed manner. With thebackup member 76 in the proximal position, the inwardly extendingfingers 98 of thebackup member 76 are engaged by the spaced arms 42 (FIG. 4) of theanvil center rod 38, such that theanvil head 40 is retained in the operative condition. As described above, theplunger finger 52 of theplunger 46 of theanvil center rod 38 is positioned to urge thecam latch 50 and theanvil head 40 about thepivot member 66 towards the tilted condition (FIG. 7). However, theanvil head 40 is prevented from pivoting until theannular knife 30 is advanced to unlock a locking assembly 100 (FIGS. 4, 5, and8-12) of thesurgical anvil assembly 26, as will be described.
With reference toFIGS. 8-12, thesurgical anvil assembly 26 may further include a lockingassembly 100 for selectively locking theanvil head 40 in each of the first, operative condition, and the second, tilted condition. The lockingassembly 100 replaces the deformable retainer members of the prior art, such as the retainer member 127 described inU.S. Patent No. 9,532,781. The deformable retainer members typically support thebackup member 76 in the proximal position and deform upon advancement of thebackup member 76 to allow for tilting of theanvil head 40. Due to the absence of the deformable retainer in the present embodiment, theanvil head 40 is capable of repeated movement between the untilted and tilted conditions.
The lockingassembly 100 generally includes an annular inner member orhousing 102, an annularouter member 104 surrounding theinner member 102, and a pair of lockingelements 106a, 106b movably coupled to theinner member 102. In embodiments, the inner andouter members 102, 104 may assume any suitable shape, such as, for example, ring-shaped, squared, triangular, or the like. Theinner member 102 is fixedly supported on a distally-facingouter surface 41 of theanvil head 40. Theanvil head 40 may have a plurality of holes 108 (FIG. 8) defined therethrough for receipt of fasteners (not explicitly shown) that fixedly attach theinner member 102 of the lockingassembly 100 to theanvil head 40. Theinner member 102 defines a plurality ofpassageways 110 defined transversely therethrough for housing arespective locking element 106a or 106b. While fourpassageways 110 are illustrated, it is contemplated that theinner member 102 may have more or less than fourpassageways 110 for accommodating a respective number of lockingelements 106a, 106b.
Thelocking elements 106a, 106b are received in thepassageways 110 of theinner member 102 and are arranged in diametrical opposition to one another. Thelocking elements 106a, 106b may be ball detents that protrude radially outward from anouter periphery 112 of theinner member 102. In embodiments, thelocking elements 106a, 106b may be any suitable biasing member that is resiliently, radially-outwardly biased. In embodiments, thelocking elements 106a, 106b may remain fixed relative to theinner member 102 whereas theouter member 104 may be flexible, such that theouter member 102 flexes outwardly upon contacting thelocking element 106a, 106b as theouter member 104 slides along theinner member 102, as will be described.
Theouter member 104 of the lockingassembly 100 surrounds theinner member 102 and is slidable relative thereto along a longitudinal axis "X" between a first, proximal position (FIG. 11), in which theouter member 104 abuts theouter surface 41 of theanvil head 40, and a second, distal position (FIG. 12), in which theouter member 104 is distally spaced from theouter surface 41 of theanvil head 40. Theouter member 104 has an inner surface orinner periphery 114 that is adjacent to and surrounds theouter periphery 112 of theinner member 102. Theinner periphery 114 of theouter member 104 has a lip orledge 116 protruding radially inward therefrom for selective interaction with thelocking elements 106a, 106b.
More particularly, in the first, proximal position (FIG. 11), thelip 116 of theouter member 104 is disposed proximally of an outer surface of thelocking elements 106a, 106b while also overlapping therewith. Due to thelip 116 of theouter member 104 overlapping thelocking elements 106a, 106b, thelocking elements 106a, 106b resist distal movement of theouter member 104 relative to theinner member 102. To distally move theouter member 104 of the lockingassembly 100, a threshold force oriented in the distal direction must be applied to theouter member 104 to overcome the spring force of thelocking elements 106a, 106b. Upon application of the threshold force, thelocking elements 106a, 106b are moved radially inward relative to theinner member 102, allowing thelip 116 of theouter member 104 to pass over the lockingelements 106a, 106b.
When theouter member 104 is in the second, distal position (FIG. 12), thelocking elements 106a, 106b and thelip 116 of theouter member 104 are engaged and aligned along a transverse axis. Since thelocking elements 106a, 106b exhibit an outwardly-oriented spring bias, thelip 116 of theouter member 104 and thelocking elements 106a, 106b are frictionally engaged with one another, thereby resisting movement of theouter member 104 from the second, distal position until the threshold force is applied in the proximal direction.
The lockingassembly 100 further includes a plurality of posts orrods 118 interconnecting theinner member 102 of the lockingassembly 100 and thebackup member 76. Theposts 118 are circumferentially spaced from one another and extend downwardly (e.g., proximally) from theouter member 104. Theposts 118 have adistal end 118b attached to or formed with theouter member 104, anintermediary portion 118c extending through arespective hole 108 defined through theanvil head 40, and aproximal end 118a disposed within therecess 70 of theanvil head 40. Theproximal end 118a of each of theposts 118 is fixed to thebackup member 76, such that thebackup member 76 moves with theouter member 104 as theouter member 104 moves relative to theinner member 102. Accordingly, as theouter member 104 moves from the first, proximal position (FIG. 11) toward the second, distal position (FIG. 12), thebackup member 76 moves deeper into therecess 70 of theanvil head 40 and out of engagement with the distal spacedarms 42 of theanvil center rod 38.
In operation, thebackup member 76 with thecut ring 78 is maintained in therecess 70 in the proximal position by the lockingassembly 100. In particular, thelocking elements 106a, 106b resist distal movement of theouter member 104 of the lockingassembly 100 relative to theinner member 102 of the lockingassembly 100. Since thebackup member 76 is fixed to theouter member 104 via theposts 118 of the lockingassembly 100, distal movement of thebackup member 76 toward the distal position is also resisted.
When theanvil head 40 and the staple cartridge 28 (FIG. 3) of theshell 24 are approximated, the staplinginstrument 10 may be fired to advance theannular knife 30 within theshell 24 from a retracted position recessed within theshell 24 to an advanced position extending into thecut ring 78 of theanvil assembly 26. As theannular knife 30 engages thecut ring 78, thecut ring 78 and thebackup member 76 exert a distally-oriented force on theouter member 104 of the lockingassembly 100 via theposts 118 of the lockingassembly 118. Upon applying the threshold force on theouter member 104, the locking element(s) 106a, 106b are forced radially-inward into therespective passageways 110 of theinner member 102, allowing thelip 116 of theouter member 104 to pass over the lockingelements 106a, 106b as thebackup member 76 is advanced to the second, distal position within therecess 70 of theanvil head 40, as shown inFIG. 11. Once thebackup member 76 moves towards its second position, thelip 116 of theouter member 104 and thelocking elements 106a, 106b frictionally engage one another to selectively fix theouter member 104 and, in turn, thebackup member 76 in the second, distal position.
As thebackup member 76 is moved toward its distal position, the fingers 98 (FIGS. 4 and 5) of thebackup member 76 disengage the distal spacedarms 42 of theanvil center rod 38, freeing theanvil head 40 to pivot relative to theanvil center rod 38. With theanvil head 40 free to rotate, the plunger spring 48 (FIG. 6) urges theplunger 46 in a distal direction whereby theplunger finger 52 engages thecam latch 50 to rotate thecam latch 50 and theanvil head 40 about thepivot member 66 to permit theanvil head 40 to assume the second tilted condition depicted inFIG. 7.
After theanvil head 40 is moved to the tilted condition, theanvil head 40 may be manually moved back towards the first, operative condition. After moving theanvil head 40 back to the first, operative condition (e.g., untilted), thebackup member 76 may also be reset to its proximal position. To move thebackup member 76 to the proximal position, a proximally-oriented threshold force may be manually applied to theouter member 104 of the lockingassembly 100, which overcomes the static friction between thelip 116 of theouter member 104 and thelocking elements 106a, 106b, whereby theouter member 104 moves proximally relative to theinner member 102. Due to the interconnection between theouter member 104 and thebackup member 76 via theposts 118, thebackup member 76 moves proximally with theouter member 104 back toward the proximal position.
Upon re-entering the proximal position, the fingers 98 (FIGS. 4 and 5) of thebackup member 76 re-engage the distal spacedarms 42 of theanvil center rod 38, thereby stabilizing theanvil head 40 in the first, operative condition. It is contemplated that this process of selectively moving theanvil head 40 relative to theanvil center rod 38 may be repeated indefinitely.
With reference toFIGS. 13-19, another embodiment of asurgical anvil assembly 126 is illustrated, similar to theanvil assembly 26 described above. Due to the similarities between theanvil assembly 126 of the present embodiment and theanvil assembly 26 described above, only those elements of theanvil assembly 126 deemed necessary to elucidate the differences fromanvil assembly 26 will be described in detail.
With specific reference toFIGS. 13 and14, theanvil assembly 126 includes ananvil center rod 138 and an anvil head 140, similar to theanvil head 40 described above. The anvil head 140 is pivotally mounted to theanvil center rod 138. Theanvil center rod 138 may include a pair of distal spacedarms 142 and an elongatedproximal body portion 144 extending proximally from the pair of distal spacedarms 142. The distal spacedarms 142 definetransverse bores 143 through a distal end thereof for receiving a pivoting member (not explicitly shown), similar to thepivot member 66 described above. Theproximal body portion 144 of theanvil center rod 138 is configured to releasably couple to an anvil retainer or trocar, such as, for example, theanvil retainer 22 shown inFIG. 2. A detailed description of an anvil retainer may be found inU.S. Pat. No. 7,364,060.
Theproximal body portion 144 of theanvil center rod 138 defines a pair of diametricallyopposed slots 150a, 150b. Theslots 150a, 150b extend proximally from a location adjacent a proximal end of the distal spacedarms 142 and terminate distally of a proximal end of theproximal body portion 144. Theslots 150a, 150b are dimensioned for receipt of a pair oflegs 152, 154 configured to releasably capture theanvil retainer 22 therebetween, as will be described below.
With reference toFIGS. 15-19, thelegs 152, 154 of theanvil center rod 138 are received within arespective slot 150a, 150b in theproximal body portion 144 of theanvil center rod 138. Each of thelegs 152, 154 is fabricated from a material that allows thelegs 152, 154 to flex aboutproximal ends 152a, 154a thereof in a spring-like manner. It is contemplated that the thickness of thelegs 152, 154 may be increased or decreased to adjust the flexibility thereof. Distal ends 152b, 154b of thelegs 152, 154 are attached to aninner periphery 156 of theproximal body portion 144 via, for example, laser welding, whereas proximal ends 152a, 154a of thelegs 152, 154 are free to pivot relative to the respectivedistal end 152b, 154b.
In embodiments, thelegs 152, 154 may be attached to theproximal body portion 144 along any suitable location of thelegs 152, 154 using any suitable fastening method. As can be appreciated, adjusting the location at which thelegs 152, 154 are attached to theproximal body portion 144 changes the force required to flex thelegs 152, 154. The proximal ends 152a, 154a of thelegs 152, 154 include a tab ordetent 158, 160 that extends radially inward. Thedetents 158, 160 are configured for snap fit engagement with alip 23 defined by a proximal end of thetrocar 22, as will be described in further detail below.
Each of thelegs 152, 154 has an outer profile that matches the outer profile of theproximal body portion 144 so that thelegs 152, 154 do not protrude outwardly from theproximal body portion 144. Each of thelegs 152, 154 has an inner profile that substantially matches an outer profile of thetrocar 22. As such, when thelegs 152, 154 are disposed within therespective slots 150a, 150b of theproximal body portion 144, thelegs 152, 154 cooperatively define acavity 162 therebetween dimensioned for receipt of thetrocar 22.
During manufacture, thelegs 152, 154 are received within arespective slot 150a, 150b of theproximal body portion 144, and thedistal end 152b, 154b of each of thelegs 152, 154 is welded (e.g., laser welded) to the inner periphery 156 (FIG. 18) of theproximal body portion 144. As shown inFIGS. 17 and 18, thetrocar 22 is distally advanced, in the direction indicated by arrows "A" inFIG. 18, through theproximal body portion 144, whereby a taperedouter surface 25 of the base of thetrocar 22 engages thedetents 158, 160 at theproximal end 152a, 154a of thelegs 152, 154, causing thelegs 152, 154 to flex outwardly. As shown inFIG. 19, distal advancement of thetrocar 22 is continued until thelip 23 defined at the base of thetrocar 22 passes over thedetents 158, 160 of thelegs 152, 154, such that thedetents 158, 160 snap into place proximally of thelip 23 of thetrocar 22, capturing thetrocar 22 in thecavity 162 defined between thelegs 152, 154. The inwardly-oriented resilient bias of thelegs 152, 154 axially fixes thetrocar 22 within theproximal body portion 144.
With reference toFIGS. 20-23, another embodiment of asurgical anvil assembly 226 is illustrated, similar to the anvil assemblies described above. Due to the similarities between theanvil assembly 226 of the present embodiment and the anvil assemblies described above, only those elements of theanvil assembly 226 deemed necessary to elucidate the differences from the other anvil assemblies will be described in detail.
Theanvil assembly 226 includes ananvil center rod 238, ananvil head 240 pivotally mounted to theanvil center rod 238, and aring assembly 250 for selectively unlocking theanvil head 240 from theanvil center rod 238. Theanvil head 240 is configured to pivot relative to theanvil center rod 238 between a first operative condition and a second pivoted or tilted condition. Theanvil head 240 defines arecess 270 therein having apost 256 of theanvil head 240 extending proximally therefrom. Thepost 256 of theanvil head 240 is pivotally coupled to a distal end of theanvil center rod 238.
Thering assembly 250 is received within therecess 270 defined in theanvil head 240 and generally includes abackup member 276 and acut ring 278 disposed about and secured to thebackup member 276. Thering assembly 240 is movable within therecess 270 of theanvil head 240 upon application of a force thereto, e.g., during advancement of an annular knife, such as, for example, theannular knife 30 shown inFIGS. 3 and6. Thebackup member 276 of thering assembly 250 has aring body 279 and anannular lip 252 extending radially outward from a distal end of thering body 279 to support thecut ring 278 thereon. Thering body 279 defines acentral opening 294 for reception of thepost 256 of theanvil head 240. Thecentral opening 294 is dimensioned to allow movement of thebackup member 276 about thepost 256 from a pre-fired, retracted or proximal position (FIG. 20) to a post-fired, advanced or distal position (FIG. 23) within therecess 70 of theanvil head 40.
Thebackup member 276 further includes a pair of diametricallyopposed fingers 298 extending inwardly from thering body 279 into thecentral opening 294. Thefingers 298 are engaged by a distal end of theanvil center rod 238 to prevent thebackup member 276 from moving in a proximal direction and to maintain theanvil head 40 in the operative condition (e.g., untilted), in a similar manner described above. Pivotal movement of theanvil head 240 relative to theanvil center rod 238 is permitted only after thefingers 298 are distally spaced from the distal end of theanvil center rod 238. Thebackup member 276 is restricted from moving distally out of the proximal position by afrangible portion 254 of thecut ring 278, as will be described below. Thebackup member 276 may be formed from a hard material such as metal, although other materials of construction are envisioned.
Thecut ring 278 of thering assembly 250 includes a disc-shapedannular body 257 defining acentral aperture 258 for reception of thebackup member 276. Theannular body 257 may be press fit onto thebackup member 276. Thus, movement of thebackup member 276 between proximal and distal positions causes corresponding movement of thecut ring 278. In embodiments, thecut ring 278 may be formed through a molding process, e.g., an injection molding process, and may be fabricated from a material having a durometer which permits theannular knife 30 to pierce through theannular body 257 and bottom out against theannular lip 252 of thebackup member 276. In embodiments, thecut ring 278 may be fabricated from a material that prevents advancement of theannular knife 30 therethrough and is instead coated with a material that permits advancement of theannular knife 30 therethrough. Suitable materials for thecut ring 278 include polytetrafluoroethylene, polypropylene or polyester. Other materials are contemplated.
As best shown inFIG. 21, thecut ring 278 includes a plurality ofpockets 258 formed in a bottom orproximal surface 260 thereof. Thepockets 258 are illustrated as having a curved shape, but it is contemplated that thepockets 258 may assume any suitable shape. Thecut ring 278 further includes a plurality of frangible portions orlegs 254 extending distally from a top ordistal surface 262 of theannular body 257 of thecut ring 278. As shown inFIG. 20, thefrangible legs 254 suspend theannular body 257 of thecut ring 278 in therecess 270 of theanvil head 240 to maintain thering assembly 250 in the proximal position. Thefrangible legs 254 may have a curved shape and are positioned directly over arespective pocket 258. Thefrangible legs 254 are configured to deform (e.g., collapse) into therespective pocket 258 upon application of a distally-oriented threshold force on thering assembly 250.
To facilitate deformation of thefrangible legs 254, thedistal surface 262 of theannular body 257 of thecut ring 278 defines a pair ofannular indentations 264 disposed on opposite sides of thefrangible legs 254. Theindentations 264 may have an arcuate, V-shaped, or any suitable cross-sectional configuration. Thefrangible legs 254 of thecut ring 278 may be fabricated from the same or a different material as theannular body 257 of thecut ring 278. For example, thefrangible legs 254 may be fabricated from polytetrafluoroethylene, polypropylene or polyester.
In operation, prior to firing of the annular knife 30 (FIGS. 3 and6), the ring assembly 250 (including thebackup member 276 and the cut ring 278) is in its retracted or proximal position. In the proximal position, thefrangible legs 254 of thecut ring 278 are in engagement with aninner surface 272 of theanvil head 240, thereby maintaining thering assembly 250 in the proximal position, as shown inFIG. 20. With thering assembly 250 in the proximal position, the inwardly extendingfingers 298 of thebackup member 276 are engaged by theanvil center rod 238, such that theanvil head 240 is retained in the first, operative condition and prevented from pivoting relative to theanvil center rod 238.
When the annular knife 30 (FIGS. 3 and6) is advanced, theannular knife 30 engages theannular body 257 of thecut ring 278 of thering assembly 250. Theannular knife 30 pierces theannular body 257 of thecut ring 278 and ultimately engages theannular lip 252 of thebackup member 276. The force applied by theannular knife 30 on thering assembly 250 is transferred to thefrangible legs 254 of thecut ring 278, which are compressed between theannular body 257 of thecut ring 278 and theinner surface 272 of theanvil head 240. Upon theannular knife 30 applying a distally-oriented threshold force on thering assembly 250, thefrangible legs 254 of thecut ring 278 detach or break from theannular body 257 of thecut ring 278 along theannular indentations 264.
With thefrangible legs 254 of thecut ring 278 detached from theannular body 257 of thecut ring 278, a continued distally-oriented force on thering assembly 250, applied via theannular knife 30, drives theannular body 257 of thecut ring 278 and thebackup member 276 distally, whereby thefrangible legs 254 of thecut ring 278 collapse or fall into therespective pockets 258 in theannular body 257 of thecut ring 278, as shown inFIG. 23. As thering assembly 250 is advanced toward the distal position, the inwardly extendingfingers 298 of thebackup member 276 disengage from the arms of theanvil center rod 238, allowing for theanvil head 240 to pivot relative to theanvil center rod 238. It is contemplated that theanvil head 240 may pivot automatically relative to theanvil center rod 238 in the same manner described above. In embodiments, theanvil head 240 may be pivoted automatically or manually via any suitable mechanism, such as those mechanisms described in the patents referenced above.
With reference toFIGS. 24-29, another embodiment of asurgical anvil assembly 326 is illustrated, similar to the surgical anvil assemblies described above. Due to the similarities between theanvil assembly 326 of the present embodiment and the anvil assemblies described above, only those elements of theanvil assembly 326 deemed necessary to elucidate the differences from the previously described anvil assemblies will be described in detail.
Theanvil assembly 326 generally includes an anvil center rod (not shown), similar to the anvil center rods described above, ananvil head 340 configured to be pivotally mounted to the anvil center rod, and aring assembly 350 configured to selectively unlock theanvil head 340 from the anvil center rod. Theanvil head 340 is configured to pivot relative to the anvil center rod between a first operative condition and a second pivoted or tilted condition.
Theanvil head 340 defines a recess 370 (FIG. 28) therein having apost 356 of theanvil head 340 extending proximally therefrom. Thepost 356 of theanvil head 340 is configured to be pivotally coupled to a distal end of the anvil center rod. Therecess 370 of theanvil head 340 is dimensioned for slidable receipt of thering assembly 350. Theanvil head 340 includes an annular, innerperipheral surface 372 that partially defines therecess 370, and an inner race or catch 374 that extends radially inward from the innerperipheral surface 372. Theinner race 374 resists, without preventing, distal movement of thering assembly 350 through therecess 370 of theanvil head 340.
Thering assembly 350 generally includes abackup member 376, similar to the backup members described above, aring cup 352 nested in thebackup member 376, and acut ring 378 nested in thering cup 352. Thering assembly 350 is moved within therecess 370 of theanvil head 340 upon application of a force thereto, e.g., during advancement of an annular knife 30 (FIGS. 28 and 29). Thebackup member 376 defines acentral opening 394 for reception of thepost 356 of theanvil head 340. Thecentral opening 394 is dimensioned to facilitate movement of thebackup member 376 about thepost 356 from a pre-fired, retracted or first position to a post-fired, advanced or second position within therecess 370 of theanvil head 340. Thebackup member 376 is retained in the proximal position by theinner race 374 of theanvil head 340, which supports thering cup 352 in the proximal position (FIG. 28), as will be described.
Thebackup member 376 includes a pair of diametricallyopposed fingers 398 extending inwardly into thecentral opening 394. Thefingers 398 are engaged by the anvil center rod to prevent thebackup member 376 from moving in a proximal direction and to maintain theanvil head 340 in the operative condition (e.g., untilted). Pivotal movement of theanvil head 340 relative to the anvil center rod is permitted only after thefingers 398 are distally spaced from the anvil center rod.
Thebackup member 376 of thering assembly 350 further includes an annular wall orring 354, and a disc-shapedplatform 357 extending radially outward from a distal portion of theannular wall 354. Theannular wall 354 has alip 358 extending radially inward from a proximal portion thereof. Thelip 358 is configured to engage (e.g., via snap-fit engagement) thering cup 352 to retain thering cup 352 with thebackup member 376. Thebackup member 376 may be formed from a hard material such as metal, although other materials of construction are envisioned.
Thering cup 352 of thering assembly 350 supports thecut ring 378 therein and guides theannular knife 30 into thecut ring 378 to prevent partial or offset cutting of thecut ring 378. Thering cup 352 is nested with thebackup member 376 by being captured between an innerperipheral surface 372 of theanvil head 340 and thebackup member 376. Thering cup 352 generally includes an annularouter wall 360, an annular, firstinner wall 362, and a disc-shapedbase 364 interconnecting theouter wall 360 and the firstinner wall 362. Theouter wall 360, thebase 364, and the firstinner wall 362 cooperatively define a cavity orannular chamber 366 dimensioned for receipt of thecut ring 352.
As best shown inFIGS. 24-27, theouter wall 360 of thering cup 352 has an annular, outerperipheral surface 360a and an annular, innerperipheral surface 360b, wherein a thickness of theannular wall 360 is defined therebetween. Anouter lip 368 extends radially outward from the outerperipheral surface 360a of theouter wall 360. Theouter lip 368 of theouter wall 360 overlaps theinner race 374 of theanvil head 340 to support thering assembly 350 in the proximal position and resist movement of thering assembly 350 toward the distal position.
Theouter wall 360 may have a plurality ofslits 380 defined therein. The slits are arranged circumferentially about theouter wall 360. Theslits 380 render theouter wall 360 flexible, such that upon distal advancement of thering assembly 350 through therecess 370 of theanvil head 340, theouter wall 360 may flex or bend radially inward to snap into place under theinner race 374 of theanvil head 340. In embodiments, instead of or in addition to having theslits 380, theouter wall 360 may be fabricated from a flexible material to facilitate radial contraction of theouter wall 360 during assembly into theanvil head 340.
Theouter wall 360 of thering cup 352 further includes a chamferedsurface 382 that slopes downwardly (e.g., distally) from a proximal-most surface of theouter wall 360. An annularinner edge 384 of the chamfered surface 382 (FIG. 27) is disposed radially inward of the innerperipheral surface 360b of theouter wall 360, such that the chamferedsurface 382 defines an undercut oroverhang 386. The undercut 386 overlays anouter edge 388 of thecut ring 378 to capture thecut ring 378 in theannular chamber 366 of thering cup 352. As such, as theannular knife 30 advances, the chamferedsurface 382 guides or redirects theknife 30 inwardly and into contact with thecut ring 378 at a location radially inward of theouter edge 388 of thecut ring 378. This eliminates the possibility of a line-to-line stapling condition.
It is contemplated that the location at which theknife 30 contacts thecut ring 378 may be adjusted by adjusting the depth of the undercut 386. For example, to ensure that theknife 30 contacts thecut ring 378 at a more radially inward location, the depth of the undercut 386 in theouter wall 360 may be increased. In addition or in the alternative to increasing the depth of the undercut 386, the annularinner edge 384 of the chamferedsurface 382 may extend a greater distance radially inward relative to the innerperipheral surface 360b of theouter wall 360 to cause theknife 30 to contact thecut ring 378 at a more radially inward location.
Thering cup 352 further includes an annular, secondinner wall 390 disposed radially inward of the firstinner wall 362. The secondinner wall 390 may be coupled to the firstinner wall 362 via a plurality ofbridge members 392 that permit the secondinner wall 390 to flex relative to the firstinner wall 362. The secondinner wall 390 may also include a plurality ofslits 395 defined therein. Theslits 395 are arranged circumferentially about the secondinner wall 390 to further facilitate flexing of the secondinner wall 390. To assemble thering cup 352 to thebackup member 376, the secondinner wall 390 of thering cup 352 is flexed radially inward and captured under thelip 358 of thebackup member 376.
Thecut ring 378 of thering assembly 350 is received in theannular chamber 366 of thering cup 352 between theouter wall 360 of thering cup 352 and the firstinner wall 362 of thering cup 352. Theouter edge 388 of thecut ring 378 is disposed under the undercut 386 of the chamferedsurface 382 of thering cup 352. It is contemplated that thecut ring 378 may be press fit onto thering cup 352. Thus, movement of thering cup 352 between proximal and distal positions causes corresponding movement of thecut ring 378. In embodiments, thecut ring 378 may be formed through a molding process, e.g., an injection molding process, and extend through a plurality of holes 397 (FIG. 26) defined through thebase portion 364 of thering cup 352.
Thecut ring 378 may be fabricated from a material having a durometer which permits theannular knife 30 to pierce through thecut ring 378 and bottom out against thebase portion 364 of thering cup 352. As such, all of thering cup 352 or select portions thereof (e.g., the chamferedsurface 382 and the base portion 364) is fabricated from a harder material than thecut ring 378. Suitable materials for thecut ring 378 include polytetrafluoroethylene, polypropylene or polyester. Other materials are contemplated.
In operation, prior to firing a circular stapling instrument having thesurgical anvil assembly 326 of the presently described embodiment, thering assembly 350 including thebackup member 376, thering cup 352, and thecut ring 378, is in its retracted or proximal position, as shown inFIG. 28. Theouter lip 368 of theouter wall 360 of thering cup 352 overlaps theinner race 374 of theanvil head 340 to support thering assembly 350 in the proximal position. With thering assembly 350 in the proximal position, the inwardly extendingfingers 398 of thebackup member 376 are engaged by the anvil center rod to maintain theanvil head 340 in the first, operative condition, as described above.
Upon actuation of the stapling instrument, theannular knife 30 is advanced into engagement with thecut ring 378 of thering assembly 350. In some instances, a section of theannular knife 30 may be out of vertical registration with the cut ring 378 (e.g., disposed radially outward). In these instances, as theknife 30 is advanced, theknife 30 engages the chamferedsurface 382 of thering cup 352, which directs theknife 30 radially inward into vertical registration with thecut ring 378. Due to the chamferedsurface 382 of thering cup 352 hanging over thecut ring 378, theknife 30 makes contact with thecut ring 378 radially inward of theouter edge 388 of thecut ring 378.
As advancement of theknife 30 is continued, theknife 30 pierces thecut ring 378 and ultimately engages thebase portion 364 of thering cup 352, as shown inFIG. 29. The force applied by theknife 30 flexes or bends theouter wall 360 of thering cup 352 inwardly to pass over theinner race 374 of theanvil head 340. Thering cup 352, along with thecut ring 378 and thebackup member 376, is then driven distally toward the distal position.
As thering assembly 350 is advanced toward the distal position, the inwardly extendingfingers 398 of thebackup member 378 disengage the anvil center rod, allowing for theanvil head 340 to pivot relative to the anvil center rod. It is contemplated that theanvil head 340 may be configured to pivot automatically relative to the anvil center rod in any manner described herein. In embodiments, theanvil head 340 may be pivoted via any suitable pivoting mechanism, whether it is automatic or manual.
With reference toFIGS. 30-32, another embodiment of asurgical anvil assembly 426 is illustrated, similar to the anvil assemblies described above. Due to the similarities between theanvil assembly 426 of the present embodiment and the anvil assemblies described above, only those elements of theanvil assembly 426 deemed necessary to elucidate the differences from anvil assemblies described above will be described in detail.
Theanvil assembly 426 generally includes an anvil center rod (not shown), similar to the anvil center rods described above, ananvil head 440 pivotally mounted to the anvil center rod, and aring assembly 450 configured to selectively unlock theanvil head 440 from the anvil center rod. Theanvil head 440 is configured to pivot relative to the anvil center rod between a first operative condition and a second pivoted or tilted condition. Theanvil head 440 defines arecess 470 therein for receipt of thering assembly 450. Theanvil head 440 includes an annular, innerperipheral surface 472 that partially defines therecess 470.
Theanvil head 440 may include a frangible retainer member (not shown), similar to the retainer member 127 described inU.S. Patent No. 9,531,781. The frangible retainer member may be disposed in therecess 470 of theanvil head 440 between the innerperipheral surface 472 of theanvil head 440 and thering assembly 450 so that upon application of a threshold distal force on thering assembly 450, the frangible retainer collapses, allowing distal advancement of thering assembly 450 and theannular knife 30.
Thering assembly 440 is received within therecess 470 defined in theanvil head 440 and generally includes abackup member 476, afirst cut ring 452 nested in thebackup member 476, and asecond cut ring 478 nested in thefirst cut ring 452. Thering assembly 450 is moved within therecess 470 of theanvil head 440 upon application of a force thereto, e.g., during advancement of theannular knife 30.
Thebackup member 476 defines acentral opening 494 for reception of apost 456 of theanvil head 440. Thecentral opening 494 is dimensioned to facilitate movement of thebackup member 476 about thepost 456 from a pre-fired, retracted or first position to a post-fired, advanced or second position within therecess 470 of theanvil head 440. Thebackup member 476, similar to the backup members described above, includes a pair of diametrically opposed fingers (not explicitly shown) extending inwardly into thecentral opening 494. The fingers are engaged by the anvil center rod to prevent thebackup member 476 from moving in a proximal direction and to maintain theanvil head 440 in the operative condition (e.g., untilted). Pivotal movement of theanvil head 440 relative to the anvil center rod is permitted only after the fingers of thebackup member 476 are distally spaced from the anvil center rod, as already described above.
Thebackup member 476 further includes an annular wall orring 454 and a disc-shaped platform 457 extending radially outward from a distal portion of theannular wall 454. Theannular wall 454 has alip 458 extending radially inward from a proximal portion thereof. Thelip 458 is configured to engage (e.g., via snap-fit engagement) thefirst cut ring 452 to retain thefirst cut ring 452 with thebackup member 476. Thebackup member 476 may be formed from a hard material such as metal, although other materials of construction are envisioned.
Thefirst cut ring 452 of thering assembly 450 supports thesecond cut ring 476 therein and provides a surface on which staples are to be cut. Thefirst cut ring 452 is fabricated from a first material, such as, for example, a hard plastic, that resists being pierced by theannular knife 30. Thefirst cut ring 452 is nested with thebackup member 476 by being captured between the innerperipheral surface 472 of theanvil head 440 and thebackup member 476. Thefirst cut ring 452 includes aproximal portion 452a, adistal portion 452b, and an annular cutout orrecess 452c disposed therebetween. Theannular recess 452c is defined in an outerperipheral surface 460 of thefirst cut ring 452 and captures thesecond cut ring 478 therein.
Thefirst cut ring 452 further defines anannular groove 462 in theproximal portion 452a thereof that extends circumferentially along aproximal surface 464 of thefirst cut ring 452. While thegroove 462 is illustrated as having a V-shaped configuration, it is contemplated that thegroove 462 may assume any suitable configuration, such as, for example, U-shaped or squared. Thegroove 462 is in vertical registration with theannular recess 452c of thefirst cut ring 452 and is configured to guide the annular knife 30 (FIG. 32) radially inward toward an apex 466 of thegroove 462.
Theproximal portion 452a of thefirst cut ring 452 has a reduced thickness defined between the apex 466 of thegroove 462 and theannular recess 452c. As such, when theannular knife 30 is advanced distally into theproximal portion 452a of thefirst cut ring 452, theannular knife 30 cuts through theproximal portion 452a of thefirst cut ring 452 along a vertical pathway "P" running through thegroove 462 of thefirst cut ring 452. The depth of thegroove 462 may be increased to increase the force necessary for theannular knife 30 to cut therethrough, or decreased to decrease the force necessary for theannular knife 30 to cut therethrough.
Thesecond cut ring 478 of thering assembly 450 is received in theannular recess 452c of thefirst cut ring 452. As mentioned above, thesecond cut ring 478 is in vertical registration with thegroove 462 of thefirst cut ring 452, such that thegroove 462 of thefirst cut ring 452 guides theannular knife 30 into thesecond cut ring 478 at a location radially inward of an outer peripheral surface of thesecond cut ring 478. It is contemplated that thesecond cut ring 478 may be press fit into theannular recess 452c of thefirst cut ring 452. Thus, movement of thefirst cut ring 452 between proximal and distal positions causes corresponding movement of thesecond cut ring 478. The relatively harderfirst cut ring 452 provides a surface on which theannular knife 30 can cut through staples without being dragged into the relatively softersecond cut ring 478, which is used to cut tissue cleanly.
In embodiments, thesecond cut ring 478 may be formed through a molding process, e.g., an injection molding process. Thesecond cut ring 478 may be fabricated from a material having a durometer which permits theannular knife 30 to pierce through thesecond cut ring 478 and bottom out against thedistal portion 452b of thefirst cut ring 452b. As such, thesecond cut ring 478 is fabricated from a softer material than thefirst cut ring 452. Suitable materials for thesecond cut ring 478 include polytetrafluoroethylene, polypropylene or polyester. Other materials are contemplated.
In operation, prior to firing a circular stapling instrument having thesurgical anvil assembly 426 of the presently described embodiment, thering assembly 450, including thebackup member 476, thefirst cut ring 452, and thesecond cut ring 478, is in its retracted or proximal position. The frangible retainer member (not explicitly shown) is interposed between thebackup member 476 and theinner surface 472 of theanvil head 440 to support thering assembly 450 in the proximal position. With thering assembly 450 in the proximal position, the inwardly extending fingers of thebackup member 476 are engaged by the anvil center rod, such that theanvil head 440 is retained in the first, operative condition.
Upon actuation of the stapling instrument, theannular knife 30 is advanced into engagement with rampedsurfaces 462a, 462b (FIG. 31) that define thegroove 462 of thefirst cut ring 452. The ramped surfaces 462a, 462b direct theknife 30 radially inward into vertical registration with a central portion of thesecond cut ring 478. Theannular knife 30 moves through thegroove 462 and contacts the apex 466 of thegroove 462, transferring the distally-oriented force to the frangible retainer member. Upon applying a threshold force on the frangible retainer member, the frangible retainer member collapses, allowing for distal movement of thering assembly 450 through therecess 470 of theanvil head 440.
As thering assembly 450 is advanced toward the distal position, the inwardly extending fingers of thebackup member 476 disengage from the anvil center rod, allowing for theanvil head 440 to pivot relative to the anvil center rod. It is contemplated that theanvil head 440 may be configured to pivot automatically relative to the anvil center rod in any manner described herein. In embodiments, theanvil head 440 may be pivoted via any suitable pivoting mechanism, whether it is automatic or manual.
As advancement of theannular knife 30 is continued, theannular knife 30 cuts through theproximal portion 452a of thefirst cut ring 452, slicing through any tissue and staples along its pathway and dissevering an outer circumferential section of theproximal portion 452a of thefirst cut ring 452 from the remainder of theproximal portion 452a of thefirst cut ring 452. It is contemplated that the outer circumferential section of thefirst cut ring 452 remains adhered, via friction, to an outer surface of theannular knife 30. As advancement of theannular knife 30 is continued, theannular knife 30 cuts through thesecond cut ring 478 and ultimately bottoms out on thedistal portion 452b of thefirst cut ring 452. In embodiments, the frangible retainer member may be configured to collapse after theannular knife 30 cuts through theproximal portion 452a of thefirst cut ring 452 rather than before.
With reference toFIGS. 33-40, another embodiment of asurgical anvil assembly 526 is illustrated, similar to the anvil assemblies described above. Due to the similarities between theanvil assembly 526 of the present embodiment and the anvil assemblies described above, only those elements of theanvil assembly 526 deemed necessary to elucidate the differences from the above anvil assemblies will be described in detail.
With reference toFIGS. 33 and34, theanvil assembly 526 generally includes an anvil center rod (not shown), similar to the anvil center rods described above, ananvil head 540 pivotally mounted to the anvil center rod, and aring assembly 550 configured to selectively unlock theanvil head 540 from the anvil center rod. Theanvil head 540 is configured to pivot relative to the anvil center rod between a first operative condition and a second pivoted or tilted condition.
Theanvil head 540 defines arecess 570 therein dimensioned for receipt of thering assembly 550. Theanvil head 540 includes apost 556 centrally located within therecess 570 and projects proximally from a floor of therecess 570. Thepost 556 pivotally couples theanvil head 540 to the anvil center rod. For example, thepost 556 of theanvil head 540 may be pivotally coupled to a pair of distal spaced arms of the anvil center rod. Thepost 556 has abody 522 having anannular ledge 524 projecting radially outward therefrom. Theannular ledge 524 is configured to selectively maintain thering assembly 550 in a pre-fired, proximal position. Thebody 522 of thepost 556 defines anannular depression 526 disposed underneath or distally of theannular ledge 524.
Thering assembly 550 is received within therecess 570 defined in theanvil head 540 and generally includes asnap collar 552 engaged to thebody 522 of thepost 556, abackup member 576 supported on thesnap collar 552, and acut ring 578 captured between thesnap collar 552 and thebackup member 576. Thering assembly 550 is moved within therecess 570 upon application of a force thereto, e.g., during advancement of an annular knife, such as, for example, annular knife 30 (FIGS. 3 and6).
With specific reference toFIGS. 35-37, thesnap collar 552 of thering assembly 550 is configured to selectively maintain thering assembly 550 in the proximal position, but allow for movement of thering assembly 550 toward the distal position upon the application of a distally-oriented threshold force thereon. Thesnap collar 552 may be a monolithically formed piece of plastic or may be constructed from a plurality of connected components. Thesnap collar 552 includes a plurality of horizontally-extending support surfaces orflanges 554, and a plurality ofvertical extensions 558 interposed between respective adjacent pairs of theflanges 554. As such, theflanges 554 andvertical extensions 558 are alternately arranged around the circumference of thesnap collar 552. Thesnap collar 552 may include fourflanges 554 arranged circumferentially about thesnap collar 552 in 90° spaced relation to one another. Similarly, thesnap collar 552 may include fourvertical extensions 558 arranged circumferentially about thesnap collar 552 in 90° spaced relation to one another. It is contemplated that thesnap collar 552 may have more or less than fourflanges 554 andvertical extensions 558.
Theflanges 554 of thesnap collar 552 may be planar and support thebackup member 576 thereon (FIG. 36), such that distal movement of thebackup member 576 causes distal movement of thesnap collar 552. Thevertical extensions 558 of thesnap collar 552 may extend proximally, at a perpendicular angle, relative to theflanges 554. Thevertical extensions 558 each include an annularinner lip 560 extending radially inward therefrom, and an annularouter lip 562 extending radially outward therefrom. The annularinner lips 560 are supported on theannular ledge 524 of thepost 556 of theanvil head 540 when thering assembly 550 is in the proximal position. The annularinner lips 560 of thesnap collar 552 resist movement of thering assembly 550 toward the distal position until the distally-oriented threshold force causes outward flexure of thevertical extensions 558, which disengages the annularinner lips 560 of thesnap collar 552 from theannular ledge 524 of thepost 556 of theanvil head 540. The annularouter lips 562 of thesnap collar 552 overlay a proximal surface of thecut ring 578 to prevent thecut ring 578 from moving relative to thesnap collar 552.
With reference toFIGS. 35, 36,38A, and 38B, thebackup member 576 includes aring body 580 defining acentral opening 594, a pair of diametricallyopposed tabs 582 extending radially inward from theannular body 594 into thecentral opening 594, and a pair of diametricallyopposed fingers 598 extending inwardly into thecentral opening 594. Thecentral opening 594 receives thepost 556 of theanvil head 540 and is dimensioned to facilitate movement of thebackup member 576 about thepost 556 from a pre-fired, retracted or first position to a post-fired, advanced or second position within therecess 570 of theanvil head 540. Thebackup member 576 is retained in the proximal position via the snap collar's 552 engagement with theannular ledge 524 of thepost 556.
Thetabs 582 of thebackup member 576 are supported on a first pair of diametricallyopposed flanges 554 of thesnap collar 552. Thetabs 582 of thebackup member 576 are configured to transfer a distally-oriented force, applied by an advancement of theannular knife 30, to thesnap collar 552. Thefingers 598 of thebackup member 576 extend radially inward from the ring body 580 a further extent than do thetabs 582 of thebackup member 576 and are received incutouts 528 in thebody 522 of thepost 556. Thefingers 598 of thebackup member 576 have afirst portion 598a extending horizontally from thering body 580 of thebackup member 576, and asecond portion 598b extending vertically upward or proximal from thefirst portion 598a. Thefirst portion 598a of each of thefingers 598 is supported on a second pair of diametricallyopposed flanges 554 of thesnap collar 552.
Thesecond portion 598b of thefingers 598 are engaged by the anvil center rod to prevent thebackup member 576 from moving in a proximal direction and to maintain theanvil head 540 in the operative condition (e.g., untilted). Pivotal movement of theanvil head 540 relative to the anvil center rod is permitted only after thefingers 598 of thebackup member 576 are distally spaced from the anvil center rod. Thebackup member 576 may be stamped from a hard material such as metal, although other materials of construction are envisioned.
With reference toFIGS. 33,35,36,39, and 40, thecut ring 578 of thering assembly 550 is supported on thebackup member 576 and has an innerperipheral surface 590 that is captured between the annularouter lip 562 of thesnap collar 552 and thetabs 582 andfingers 598 of thebackup member 576. Accordingly, proximal or distal movement of thebackup member 576 results in a corresponding proximal or distal movement of thesnap collar 552 and thecut ring 578. Thecut ring 578 has a plurality of surface features 596 protruding from an outer peripheral surface thereof. The surface features 596 are press fit under aninner race 574 of theanvil head 540 to retain thering assembly 550 in therecess 570.
Thecut ring 578 may be fabricated from a material having a durometer which permits theannular knife 30 to pierce through thecut ring 578 and bottom out against thering body 580 of thebackup member 576. As such, thebackup member 576 may be fabricated from a harder material than thecut ring 578. Suitable materials for thecut ring 578 include polytetrafluoroethylene, polypropylene or polyester. Other materials are contemplated.
In operation, prior to firing of a circular stapling instrument having thesurgical anvil assembly 526 of the presently described embodiment, thering assembly 550, including thebackup member 576, thesnap collar 552, and thecut ring 578, is in its retracted or proximal position in therecess 570 of theanvil head 540, as shown inFIG. 39. The annularinner lips 560 of thesnap collar 552 are supported on theannular ledge 524 of thepost 556 of theanvil head 540, and the surface features 596 of thecut ring 578 are supported on theinner race 574 of theanvil head 540. With thering assembly 550 in the proximal position, the inwardly extendingfingers 598 of thebackup member 576 are engaged by the anvil center rod, such that theanvil head 540 is retained in the first, operative condition.
Upon actuation of the stapling instrument, the annular knife is advanced into engagement with thecut ring 578 of thering assembly 550, which transfers the distally-oriented force to thebackup member 576, which in turn transfers the distally-oriented force to thesnap collar 552. Upon achieving a threshold force, thevertical extensions 558 of thesnap collar 552 flex outwardly to separate the annularinner lips 560 of thesnap collar 552 from theannular ledge 524 of thepost 556 of theanvil head 540.
With the annularinner lips 560 of thesnap collar 552 out of overlapping engagement with theannular ledge 524 of thepost 556 of theanvil head 540, the distally-oriented force imparted by the annular knife drives thering assembly 550 distally, whereby thebackup member 576 contacts theinner surface 572 of theanvil head 540, and the annularinner lips 560 of thesnap ring 552 are received in thedepression 526 of thepost 556 of theanvil head 540, as shown inFIG. 40. Continued advancement of the annular knife causes the annular knife to pierce thecut ring 578 and ultimately bottom out against thering body 580 of thebackup member 576.
In embodiments, thecut ring 578 and thesnap collar 552 may be configured such that the annular knife cuts through thecut ring 578 prior to moving thesnap collar 552 out of engagement with theannular ledge 524 of thepost 556 of theanvil head 554.
As thering assembly 550 is advanced toward the distal position, the inwardly extendingfingers 598 of thebackup member 576 disengage from the arms of the anvil center rod, allowing for theanvil head 540 to pivot relative to the anvil center rod. It is contemplated that theanvil head 540 may be configured to pivot automatically relative to the anvil center rod in any manner described herein. In embodiments, theanvil head 540 may be pivoted via any suitable pivoting mechanism, whether it is automatic or manual.
With reference toFIGS. 41-44, an embodiment according to the invention of asurgical anvil assembly 626 is illustrated, similar to the anvil assemblies described above. Due to the similarities between theanvil assembly 626 of the present embodiment and the anvil assemblies described above, only those elements of theanvil assembly 626 deemed necessary to elucidate the differences from the above anvil assemblies will be described in detail.
Theanvil assembly 626 includes ananvil center rod 638 and ananvil head 640 pivotally mounted to theanvil center rod 638. Theanvil head 640 is adapted to pivot between a first operative condition depicted inFIG. 41 and a second pivoted or tilted condition depicted inFIG. 44. Theanvil head 640 includes ahousing 654 having apost 656 and an anviltissue contact surface 658. Thepost 656 may include a pair of spaced post arms defining transverse bores 664 extending through the spaced post arms. Theanvil center rod 638 is at least partially positioned about thepost 656 and coupled to theanvil head 640 through apivot member 666.
Theanvil center rod 638 may include a pair of distal spacedarms 642 defining a pair of diametrically opposed, longitudinally-extendingslots 662. The distal spacedarms 642 includes a distal end through which transverse bores 644 are defined for receiving thepivot member 666 that pivotally couples thepost 656 of theanvil head 640 to the distal spacedarms 642 of theanvil center rod 638. Thepivot member 666 is coupled to a first location "L1" of thepost 656 of theanvil head 640 and which is aligned with a central longitudinal axis "X" defined by theanvil center rod 638.
Theanvil assembly 626 further includes a pivotingassembly 600, which replaces the conventional plunger and cam latch assembly for driving the tilting of theanvil head 640. The pivotingassembly 600 is at least partially received within theanvil center rod 638, e.g., between the spacedarms 642, and is spring biased in a proximal direction by a biasingmember 602, such as, for example, a coil spring. The pivotingassembly 600 includes alinkage arm 604 received in one of theslots 662 of the distal spacedarms 642 of theanvil center rod 638. Thelinkage arm 604 has an L-shaped configuration and includes anelongated shaft 606 and a foot orflange 608 extending perpendicularly from aproximal end 606a of theshaft 606. In embodiments, thelinkage arm 604 may assume any suitable shape, such as, for example, linear, curved, or the like. Thefoot 608 of thelinkage arm 604 has a detent or post 610 extending distally therefrom for supporting the biasingmember 602 of the pivotingassembly 600.
Theshaft 606 of thelinkage arm 604 is disposed off-center from the central longitudinal axis "X" of theanvil center rod 638. Theshaft 606 has adistal end 606b pivotally coupled to a second location "L2" of thepost 656 of theanvil head 640 via apivot member 612, such as, for example, a pin. The second location "L2" of thepost 656 of theanvil head 640 at which theshaft 606 is pivotally coupled is both distal and laterally offset from the first location "L1" at which theanvil center rod 638 is pivotally coupled to thepost 656 of theanvil head 640. As such, a longitudinal translation of theshaft 606 in the proximal or distal direction effects a pivoting of theanvil head 640 about the first location "L1" in a counter-clockwise or clockwise direction, respectively.
The biasingmember 602 of the pivotingassembly 600 is disposed within theanvil center rod 638 and in alignment with the central longitudinal axis "X" of theanvil center rod 638 and the first location "L1." The biasingmember 602 defines abore 614 therethrough that receives thedetent 610 of thefoot 608 of thelinkage arm 604 to support the biasingmember 602. The biasingmember 602 is interposed between thefoot 608 of thelinkage arm 604 and thepost 656 of theanvil head 640 while being in a compressed state. As such, thecompressed biasing member 602 exerts a proximally-oriented force on thefoot 608 of thelinkage arm 604, which is transferred to the second location "L2" of thepost 656 of theanvil head 640. Accordingly, upon unlocking theanvil head 640 from theanvil center rod 638, the biasingmember 602 drives or pulls theanvil head 640 toward the second, tilted condition, as will be described.
Theanvil assembly 626 may further include a backup member (not shown) and a cut ring (not shown), similar to the backup members and cut rings described above. The backup member is moved within arecess 670 defined in thehousing 658 of theanvil head 640 upon application of a force thereto, e.g., during advancement of an annular knife 30 (FIGS. 3 and6).
In operation, prior to firing of a circular stapling instrument having thesurgical anvil assembly 626 of the presently described embodiment, the backup member is in its retracted or proximal position in therecess 670 of theanvil head 640. With the backup member in the proximal position, the backup member is engaged by the spacedarms 642 of theanvil center rod 638, such that theanvil head 640 is retained in the first, operative condition and prevented from pivoting despite the proximally-oriented force exerted by the biasingmember 602 on theanvil head 640 via thelinkage arm 604.
Upon actuation of the stapling instrument, the annular knife is advanced into engagement with the cut ring, which transfers the distally-oriented force to the backup member, as described in previous embodiments. As the backup member is advanced toward the distal position, the backup member disengages from thearms 642 of theanvil center rod 638, unlocking theanvil head 640 from theanvil center rod 638. With theanvil head 640 unlocked from theanvil center rod 638, e.g., theanvil head 640 is free to pivot, the biasingmember 602 of the pivotingassembly 600 drives thelinkage arm 604 in a proximal direction, whereby thelinkage arm 604 pivots theanvil head 640 relative to theanvil center rod 638 in the counter-clockwise direction, indicated by arrow "B" inFIG. 44. After theanvil head 640 pivots to the second, tilted condition, theanvil head 640 covers thelinkage arm 604, preventing thelinkage arm 604 from getting caught on tissue during removal of thesurgical anvil assembly 626 from a surgical site.
During some operations, theanvil head 640 may be manually pivoted back to the first, operative condition against the spring bias of the biasingmember 602. In such instances, as theanvil head 640 is pivoted back to the first, operative condition, thelinkage arm 604 is driven or pulled in a distal direction and the biasingmember 602 is compressed between thefoot 608 of thelinkage arm 604 and thepost 656 of theanvil head 640, resetting the pivotingassembly 600.
With reference toFIGS. 45-48, another embodiment of asurgical anvil assembly 726 is illustrated, similar to the anvil assemblies described above. Due to the similarities between theanvil assembly 726 of the present embodiment and the anvil assemblies described above, only those elements of theanvil assembly 726 deemed necessary to elucidate the differences from the above anvil assemblies will be described in detail.
Theanvil assembly 726 includes ananvil center rod 738 and ananvil head 740 pivotally mounted to theanvil center rod 738. Theanvil head 740 is adapted to pivot between a first, operative condition and a second, pivoted or tilted condition. Theanvil center rod 738 may include a pair of distal spacedarms 742 for capturing a 756 post of theanvil head 740 therebetween. The distal spacedarms 742 of theanvil center rod 738 definestransverse bores 744 therethrough for receiving apivot member 766, as will be described.
Theanvil head 740 includes ahousing 754 defining arecess 770 therein and thepost 756 is centrally disposed within therecess 770 and extends proximally therefrom. Thepost 756 includes a pair of spaced postarms 760 defining aslot 762 dimensioned to capture acam latch 750 therein. The spaced postarms 760 definetransverse bores 764 therethrough dimensioned for receipt of thepivot member 766. Theanvil center rod 738 is at least partially positioned about thepost 756 and coupled to theanvil head 740 through thepivot member 766 which extends through respectivetransverse bores 744, 764 of the distal spacedarms 742 of theanvil center rod 738 and the spaced postarms 760 of thepost 756 to pivotally couple theanvil head 740 to theanvil center rod 738.
With reference toFIGS. 45 and46, thecam latch 750 is received within theslot 762 defined between the spaced postarms 760 of thepost 756 and coupled to theanvil center rod 738 and thepost 756 via thepivot member 766. Thecam latch 750 defines a bore or pin opening 752 through which thepivot member 766 extends. Thepin opening 752 in thecam latch 750 is defined by an annularinner surface 753 of thecam latch 750. Thecam latch 750 has a proximally-locatededge 757 engaged to aplunger 746 for driving a rotation of thecam latch 750. Thecam latch 750 is rotationally fixed within theslot 762 of thepost 756 of theanvil head 740, such that as thecam latch 750 rotates, due to a spring bias of theplunger 746, theanvil head 740 rotates with thecam latch 750 relative to theanvil center rod 738.
As briefly mentioned above, thepivot member 766 extends through the transverse bores 744 of the distal spacedarms 742 of theanvil center rod 738, the transverse bores 764 of the spaced postarms 760 of thepost 756, and the pin opening 752 of thecam latch 750 to allow for pivoting or rotation of theanvil head 740 relative to theanvil center rod 738. Thepivot member 766 extends through thebores 744, 764 and thepin opening 752 in a slip fit manner to ease assembly.
Thepivot member 766 is an elongated pin-like structure having opposing first andsecond ends 766a, 766b and anintermediate portion 766c disposed therebetween. It is contemplated that the first andsecond ends 766a, 766b and theintermediate portion 766c of thepivot member 766 may be monolithically formed. Anannular groove 780 is formed in anouter surface 782 of thepivot member 766. Theannular groove 780 is disposed along theintermediate portion 766c of thepivot member 766. Accordingly, the first andsecond ends 766a, 766b of thepivot member 766 have a first diameter, and theintermediate portion 766c of thepivot member 766 has a second diameter, less than the first diameter.
Thegroove 780 in thepivot member 766 may be cylindrical and extend circumferentially about theintermediate portion 766c of thepivot member 766. As such, thegroove 780 has steppedportions 784a, 784b on opposite sides thereof to limit lateral movement of thepivot member 766 within and relative to the pin opening 752 of thecam latch 750. The diameter of theintermediate portion 766c is less than the diameter of the pin opening 752 of thecam latch 750. This allows for a simplified slip fit of thepivot member 766 into the pin opening 752 of thecam latch 750 during assembly.
With reference toFIGS. 45-48, theinner surface 753 of thecam latch 750 has aproximal portion 755 that is received in thegroove 780 of thepivot member 766 and which is spring biased into contact with theouter surface 782 of thepivot member 766 via theplunger 746, as will be described. The length of thegroove 780 is greater than the thickness of thecam latch 750 to allow for some lateral movement of thepivot member 766 within the pin opening 752 of thecam latch 750.
Theanvil assembly 726 further includes theplunger 746 and aplunger spring 748. Theplunger 746 is at least partially received within theanvil center rod 738, e.g., between the spacedarms 742, and is spring biased in a distal direction by theplunger spring 748. Theplunger 746 includes aplunger finger 759 engaged to theproximal edge 757 of thecam latch 50 to maintain theproximal portion 755 of the inner surface 653 of thecam latch 750 in thegroove 780 of thepivot member 766. Due to the spring bias of theplunger 746 on thecam latch 750, theproximal portion 755 of theinner surface 753 of thecam latch 750 is frictionally engaged with theouter surface 782 of thepivot member 766 to retain thepivot member 766 in the pin opening 752 of thecam latch 750.
Theanvil assembly 726 further includes abackup member 776 and acut ring 778, similar to the backup members and cut rings described above. Thebackup member 776 is moved within therecess 770 of theanvil head 740 upon application of a force thereto, e.g., during advancement of an annular knife 30 (FIGS. 3 and6). Thebackup member 776 includes a pair of diametrically opposed fingers (not explicitly shown) extending inwardly. The fingers are engaged by the spacedarms 742 of theanvil center rod 738 to prevent thebackup member 776 from moving in a proximal direction and to maintain theanvil head 740 in the operative condition (e.g., untilted). Pivotal movement of theanvil head 740 relative to theanvil assembly 726 is permitted only after the fingers 798 are distally spaced from thearms 742 of theanvil center rod 738, as described in the previous embodiments.
In operation, prior to firing of a circular stapling instrument having thesurgical anvil assembly 726 of the presently described embodiment, the backup member 676 is in its retracted or proximal position in the 770 recess of theanvil head 740. With thebackup member 776 in the proximal position, the inwardly extending fingers of thebackup member 776 are engaged by the spacedarms 742 of theanvil center rod 738, such that theanvil head 740 is retained in the first, operative condition and prevented from pivoting despite the distally-oriented force exerted by theplunger 746 on theanvil head 740 via thecam latch 750.
Upon actuation of the stapling instrument, theannular knife 30 is advanced into engagement with thecut ring 778, which transfers the distally-oriented force to thebackup member 776. As thebackup member 776 is advanced toward the distal position, the inwardly extending fingers of thebackup member 776 disengage from thearms 742 of theanvil center rod 738, unlocking theanvil head 740 from theanvil center rod 738. With theanvil head 740 unlocked from the anvil center rod 738 (e.g., theanvil head 740 is free to pivot), the springbiased plunger 746 drives a rotation of thecam latch 750 about thepivot member 766. Due to thecam latch 750 being rotationally fixed within theanvil head 740, theanvil head 740 is caused to rotate relative to theanvil center rod 738 about thepivot member 766. In embodiments, thepivot member 766 may rotate with theanvil head 740.
With reference toFIGS. 49-52, another embodiment of asurgical anvil assembly 826 is illustrated, similar to the anvil assemblies described above. Due to the similarities between theanvil assembly 826 of the present embodiment and the anvil assemblies described above, only those elements of theanvil assembly 826 deemed necessary to elucidate the differences from the anvil assemblies above will be described in detail.
Theanvil assembly 826 includes ananvil center rod 838 and ananvil head 840 pivotally mounted to theanvil center rod 838. Theanvil head 840 is adapted to pivot between a first, operative condition and a second, pivoted or tilted condition (FIGS. 49 and52). Theanvil center rod 838 may include a pair of distal spacedarms 842 for capturing apost 856 of theanvil head 840 therebetween. The distal spacedarms 842 of theanvil center rod 838 define transverse bores therethrough for receiving apivot member 866.
Theanvil head 840 defines arecess 870 therein. Thepost 856 is centrally disposed within therecess 870 and extends proximally therefrom. Thepost 856 includes a pair of spaced postarms 860 defining aslot 862 dimensioned to capture acam latch 850 therein. The spaced postarms 860 definetransverse bores 864 therethrough dimensioned for receipt of thepivot member 866. Theanvil center rod 838 is at least partially positioned about thepost 856 and coupled to theanvil head 840 through thepivot member 866 which extends through respective transverse bores of the distal spacedarms 842 of theanvil center rod 838 and the spaced postarms 860 of thepost 856 to pivotally couple theanvil head 840 to theanvil center rod 838. Thepost 856 further includes a pair offlanges 880 projecting proximally from the respective pair of postarms 860. Theflanges 880 each have avertical surface 882 projecting perpendicularly from arounded surface 884 of therespective post arms 860.
Thecam latch 850 is received between the spaced postarms 860 of thepost 856 and between theflanges 880. Thecam latch 850 is coupled to theanvil center rod 838 and thepost 856 via thepivot member 866 which extends through a bore or pin opening 868 of thecam latch 50. As best shown inFIG. 51, thecam latch 850 has an outerperipheral surface 852 that includes acamming region 852a and a notchedregion 852b contiguous with thecamming region 852a. Thecamming region 852a may have an arcuate shape and is configured to be engaged with a plunger 846 (FIG. 52) that drives a rotation of thecam latch 850.
The notchedregion 852b of thecam latch 850 has a profile that matches a profile cooperatively defined by thevertical surface 882 of theflanges 880 and therounded surface 884 of the spaced postarms 860. The notchedregion 852b includes astop surface 854 that extends substantially radially inward from an end of thecamming region 852b. Thestop surface 854 is configured to engage aplunger finger 857 of theplunger 846 upon theanvil head 840 entering the second, titled condition, as shown inFIGS. 49 and52. Thecam latch 850 is rotationally fixed within theslot 862 of thepost 856 of theanvil head 840, such that as thecam latch 850 rotates, due to a spring bias of theplunger 846, theanvil head 840 rotates with thecam latch 850 relative to theanvil center rod 838.
Theanvil assembly 826 further includes theplunger 846 and aplunger spring 848. Theplunger 846 is at least partially received within theanvil center rod 838, e.g., between the spacedarms 842, and is spring biased in a distal direction by theplunger spring 848. Theplunger spring 848 has a spring constant high enough to prevent a manual compression of theplunger spring 848. As such, manual pivoting of theanvil head 840 from the tilted condition back towards the untilted condition is resisted by theplunger spring 848.
Theplunger 846 includes theplunger finger 857 at its distal end, which is engaged to thecamming region 852a of thecam latch 850 to bias thecam latch 850 and, in turn, theanvil head 840, toward the second, tilted condition. When theanvil head 840 is free to pivot relative to theanvil center rod 838, theplunger finger 857 pushes against thecamming region 852a of thecam latch 850, whereby thecamming region 852a of thecam latch 850 rides along theplunger finger 857, rotating theanvil head 840. Upon theanvil head 840 entering the second, tilted condition, the notchedregion 852b of thecam latch 850 passes over theplunger finger 857, whereby thestop surface 854 of thecam latch 850 is positioned in contact with theplunger finger 857. Due to the contact between thestop surface 854 of thecam latch 850 and theplunger finger 857, rotation of thecam latch 850 in the opposite direction (e.g., rotation of theanvil head 840 back toward the first, operative condition) is resisted by theplunger 846 and theplunger spring 848.
Theanvil assembly 826 further includes abackup member 876 and acut ring 878, similar to the backup members and cut rings described above. Thebackup member 876 is moved within therecess 870 of theanvil head 840 upon application of a force thereto, e.g., during advancement of the annular knife 30 (FIGS. 3 and6). Thebackup member 876 includes a pair of diametricallyopposed fingers 898 extending inwardly. Thefingers 898 are engaged by the spacedarms 842 of theanvil center rod 838 to prevent thebackup member 876 from moving in a proximal direction and to maintain theanvil head 840 in the operative condition (e.g., untilted). Pivotal movement of theanvil head 840 relative to theanvil assembly 826 is permitted only after thefingers 898 are distally spaced from thearms 842 of theanvil center rod 838.
In operation, prior to firing of a circular stapling instrument having thesurgical anvil assembly 826 of the presently described embodiment, thebackup member 876 is in its retracted or proximal position in therecess 870 of theanvil head 840. With thebackup member 876 in the proximal position, the inwardly extendingfingers 898 of thebackup member 876 are engaged by the spacedarms 842 of theanvil center rod 838 such that theanvil head 840 is retained in the first, operative condition and prevented from pivoting despite the distally-oriented force exerted by theplunger 846 on theanvil head 840 via thecam latch 850.
Upon actuation of the stapling instrument, theannular knife 30 is advanced into engagement with thecut ring 878, which transfers the distally-oriented force to thebackup member 876. As thebackup member 876 is advanced toward the distal position, the inwardly extendingfingers 898 of thebackup member 876 disengage from thearms 842 of theanvil center rod 838, unlocking theanvil head 840 from theanvil center rod 838, as described in detail above. With theanvil head 840 unlocked from the anvil center rod 838 (e.g., theanvil head 840 is free to pivot), the springbiased plunger 846 drives a rotation of thecam latch 850. Due to thecam latch 850 being rotationally fixed within theanvil head 840, theanvil head 840 is caused to rotate relative to theanvil center rod 838.
Upon theanvil head 840 rotating to the second, tilted condition, theplunger 846 is received in the notchedregion 852b of thecam latch 850, whereby thestop surface 854 of the notchedregion 852b of thecam latch 850 overlaps with theplunger finger 857. As such, an attempt to rotate theanvil head 840 back toward the first, operative condition will be resisted by the distally-oriented force exerted on the notchedregion 852b of thecam latch 850 by the springbiased plunger 846. As noted above, the biasingmember 848 has a spring constant high enough to resist a manual attempt at resetting theanvil head 840.
With reference toFIGS. 53-55, another embodiment of asurgical anvil assembly 926 is illustrated, similar to the anvil assemblies described above. Due to the similarities between theanvil assembly 926 of the present embodiment and the anvil assemblies described above, only those elements of theanvil assembly 926 deemed necessary to elucidate the differences from anvil assemblies described above will be described in detail.
Theanvil assembly 926 generally includes an anvil center rod (not shown), similar to the anvil center rods described above, ananvil head 940 pivotally mounted to the anvil center rod, and aring assembly 950 configured to selectively unlock theanvil head 940 from the anvil center rod. Theanvil head 940 is configured to pivot relative to the anvil center rod between a first operative condition and a second pivoted or tilted condition.
Theanvil head 940 includes aninner surface 972 defining arecess 970 therein dimensioned for receipt of thering assembly 950. Theinner surface 972 has anouter periphery 973 that defines anannular groove 975 therein. Thegroove 975 extends radially outward from therecess 970 and is in communication therewith. Thegroove 975 is disposed adjacent atissue contacting surface 958 of theanvil head 940 and extends circumferentially about theouter periphery 973 of theinner surface 972 of theanvil head 940. A height of thegroove 975 is defined between aproximal ledge 975a and adistal ledge 975b thereof.
Thering assembly 940 includes abackup member 976, similar tobackup member 476 described above, and acut ring 978. Thebackup member 976 is received in therecess 970 of theanvil head 940, and thecut ring 978 is nested in thebackup member 976. The cut ring includes an annularinner body portion 978a and an annularouter body portion 978b integrally formed with, and disposed circumferentially about, theinner body portion 978a. The inner andouter body portions 978a, 978b may be formed from a unitary piece of polytetrafluoroethylene, polypropylene or polyester. Other materials are contemplated. In some embodiments, theouter body portion 978b may be a separate piece attached to theinner body portion 978a.
Theinner body portion 978a of thecut ring 978 is supported on thebackup member 976 and is disposed in therecess 970 of theanvil head 940, and theouter body portion 978b of thecut ring 978 is captured between the proximal anddistal ledges 975a, 975b of thegroove 975 of theanvil head 940. Thecut ring 978 has a greater diameter than the diameter of therecess 970 of theanvil head 940, such that thecut ring 978 may be press-fit into therecess 970 during assembly. Once assembled, theouter body portion 978b of thecut ring 978 extends radially beyond thebackup member 976. Due to theouter body portion 978b of thecut ring 978 overlapping with the proximal anddistal ledges 975a, 975b, both proximal and distal movement of theouter body portion 978b of thecut ring 978 out of thegroove 975 is resisted. Theouter body portion 978b of thecut ring 978 may have a reduced thickness in relation to theinner body portion 978a to allow for some play of theouter body portion 978b of thecut ring 978 within thegroove 975, as will be described. In embodiments, the height of theinner body portion 978a of thecut ring 978 may be substantially similar to or the same as the height of thegroove 975.
In operation, prior to firing a circular stapling instrument having thesurgical anvil assembly 926 of the presently described embodiment, thering assembly 950, including thebackup member 976 and thecut ring 978, is in its retracted or proximal position. A frangible retainer member (not explicitly shown) is interposed between thebackup member 976 and theinner surface 972 of theanvil head 940 to support thering assembly 950 in the proximal position, as shown inFIG. 53. With thering assembly 950 in the proximal position, thebackup member 976 is engaged by the anvil center rod, such that theanvil head 940 is retained in the first, operative condition.
Upon actuation of the stapling instrument, an annular knife, such as, for example, theannular knife 30 shown inFIG. 6, is advanced into engagement with thecut ring 978 and dissevers or shears off theouter body portion 978b of thecut ring 978 from theinner body portion 978a of thecut ring 978. Upon cutting through thecut ring 978, theannular knife 30 engages thebackup member 976, thereby driving thebackup member 976 toward the distal position.
Due to theinner body portion 978a of thecut ring 978 being retained with thebackup member 976, theinner body portion 978a moves toward the distal position with thebackup member 976. Theouter body portion 978b of thecut ring 978 is captured between theouter periphery 973 of theinner surface 972 of theanvil head 940 and an outer surface of theannular knife 30. Thus, as shown inFIG. 54, theouter body portion 978b of thecut ring 978 is held in thegroove 975 as theinner body portion 978a of thecut ring 978 is distally advanced.
As thering assembly 950 is advanced toward the distal position, thebackup member 976 disengages from the anvil center rod, allowing for theanvil head 940 to pivot relative to the anvil center rod. It is contemplated that theanvil head 940 may be configured to pivot automatically relative to the anvil center rod in any manner described herein. In embodiments, theanvil head 940 may be pivoted via any suitable pivoting mechanism, whether it is automatic or manual.
With reference toFIG. 55, a retraction of theannular knife 30 back to its starting position causes theouter body portion 978b of thecut ring 978 to move proximally within thegroove 975 due to the frictional engagement between an outer surface of theannular knife 30 and an innerperipheral surface 979 of theouter body portion 978b of thecut ring 978. Theouter body portion 978b of thecut ring 978 is dragged proximally by the retractingannular knife 30 until theouter body portion 978b of thecut ring 978 contacts theproximal ledge 975a. With theouter body portion 978b of thecut ring 978 in contact with theproximal ledge 975a, theouter body portion 975b and theinner body portion 978a are axially spaced from one another, creating apassage 982 through which staples lodged in thecut ring 978 may be removed.
Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.

Claims

A surgical anvil assembly (626) for use with a circular stapling instrument, comprising:
an anvil center rod (638);
an anvil head (640) having a post (656) pivotally coupled to the anvil center rod, the anvil head being movable relative to the anvil center rod between a first, operative condition and a second, tilted condition; and
a pivoting assembly (600) received in the anvil center rod and including:
a linkage arm (604) including:
an elongated shaft (606) having a distal end (606b) pivotally coupled to the post of the anvil head; and
a foot (608) extending laterally from a proximal end (606a) of the shaft; and
a biasing member (602) being supported on the foot and resiliently biasing the linkage arm in a proximal direction, wherein upon the anvil head being free to move out of the first, operative condition, the biasing member drives the linkage arm in the proximal direction to pivot the anvil head relative to the anvil center rod and the linkage arm toward the second, tilted condition;
characterised in that the shaft of the linkage arm is laterally offset from a central longitudinal axis ("X") of the anvil center rod.
The surgical anvil assembly (626) according to claim 1, wherein the linkage arm (604) has an L-shaped configuration.
The surgical anvil assembly (626) according to any preceding claim, wherein the biasing member (602) is interposed between the foot (608) of the linkage arm (604) and the post (656) of the anvil head (640).
The surgical anvil assembly (626) according to any preceding claim, wherein the foot (608) has a detent (610) received in a bore (614) defined through the biasing member (602).
The surgical anvil assembly (626) according to any preceding claim, wherein the biasing member (602) is a coil spring.
The surgical anvil assembly (626) according to any preceding claim, wherein the biasing member (602) is aligned with the central longitudinal axis ("X") of the anvil center rod (638).
The surgical anvil assembly (626) according to any preceding claim, wherein the anvil center rod (638) is pivotally coupled to a first location ("L1") of the post (656) of the anvil head (640), and the distal end (606b) of the shaft (606) of the linkage arm (604) is pivotally coupled to a second location ("L2") of the post of the anvil head, the second location being laterally offset from the first location.
The surgical anvil assembly (626) according to claim 7, wherein the second location ("L2") is distal of the first location ("L1").
The surgical anvil assembly (626) according to any preceding claim, wherein the anvil head (640) covers the linkage arm (604) when the anvil head is in the second, tilted condition.
The surgical anvil assembly (626) according to any preceding claim, wherein the anvil center rod (638) defines a longitudinally-extending slot (662) through which the linkage arm (604) movably extends.
The surgical anvil assembly (626) according to any preceding claim, further including a backup member (76) and a cut ring (78) movable within a recess (670) defined in a housing (658) of the anvil head (640) upon application of a force thereto, wherein the backup member is engaged by a pair of spaced arms (642) of the anvil center rod (638) when the backup member is in the proximal position, such that the anvil head (640) is retained in the first, operative condition.